The invention concerns a transmitter unit, especially for a hydraulic brake system or for a hydraulic clutch system, comprising a housing body, a piston which is arranged in the housing body able to move between a starting disposition and a pressure position, a pressure chamber bounded by the housing body and the piston, a reservoir for the supply of hydraulic fluid connected by a connection channel to the pressure chamber, a valve unit, which in an open position allows the connection between the reservoir and the pressure chamber and in a closed position breaks this connection, as well as a connection opening for the routing of pressurized hydraulic fluid from the pressure chamber for example to a connected hydraulic brake cylinder.
Such transmitter units are known in the prior art.
However, these have the problem that air bubbles can collect in the pressure chamber and only escape from the pressure chamber with difficulty.
This has the drawback of making more difficult the putting of the hydraulic fluid in the pressure chamber under pressure, on account of the great compressibility of the air bubbles, and sometimes it is no longer even possible to do so.
Therefore, the problem which the invention proposes to solve is to improve a transmitter unit of this kind so that an escaping of air bubbles from the pressure chamber is more easily possible.